qcacld-3.0: Fix Static Analyze defect in sme_qos_ft_handoff_required()

In function sme_qos_ft_handoff_required(), CSR_GET_SESSION() is
possible to return NULL pointer, so add check before de-reference it.

Change-Id: Iee4e1d03da550969b4da1b746e4325f59ab72146
CRs-Fixed: 2669223

core/sme/src/qos/sme_qos.c

@@ -4726,7 +4726,8 @@ static bool sme_qos_ft_handoff_required(struct mac_context *mac,
 
 	csr_roam_session = CSR_GET_SESSION(mac, session_id);
 
-	if (csr_roam_session->roam_synch_in_progress &&
+	if (csr_roam_session &&
+	    csr_roam_session->roam_synch_in_progress &&
 	    csr_roam_is_ese_assoc(mac, session_id) &&
 	    csr_roam_session->connectedInfo.nTspecIeLength)
 		return true;